Method and apparatus for excluding line piece group corresponding to palm

ABSTRACT

The present application provides a method for determining mistaken approaching/touching event, comprising: gathering one or more touch sensitive signal value corresponding to a line piece; calculating a sum of differences of each signal value and a baseline value; and if the sum is less than or equals to zero, determining the line piece is corresponding to a mistaken approaching/touching event.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/564,947, filed on Sep. 9, 2019, which is acontinuation application of U.S. Pat. No. 10,429,991, filed on Dec. 31,2014 which is a continuation-in-part application of U.S. Pat. No.9,367,172, filed on Dec. 4, 2014 which claims priority to U.S.provisional patent application 61/912,078, filed on Dec. 5, 2013, toU.S. provisional patent application 61/911,564, filed on Dec. 4, 2013,and to Taiwan patent application 103117027, filed on May 14, 2014, thedisclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to detecting approaching or touching eventon touch screen, and more particularly, to determining mistakenapproaching or touching event caused by ghost point or water spot.

2. Description of the Prior Art

Among approaching or touching events detected above touch screen, someof them are mistakenly caused by ghost points or water spots. Thesemistaken approaching or touching events may lead to error userinstructions and unrecoverable consequences. Hence, there are needs formethod and apparatus for determining mistaken approaching or touchingevent in order to prevent unwanted consequences.

From the above it is clear that prior art still has shortcomings. Inorder to solve these problems, efforts have long been made in vain,while ordinary products and methods offering no appropriate structuresand methods. Thus, there is a need in the industry for a novel techniquethat solves these problems.

SUMMARY OF THE INVENTION

One objective of the present application is to provide a method fordetermining mistaken approaching/touching event, comprising: gatheringone or more touch sensitive signal value corresponding to a line piece;calculating a sum of differences of each signal value and a baselinevalue; and if the sum is less than or equals to zero, determining theline piece is corresponding to a mistaken approaching/touching event.

One objective of the present application is to provide an apparatus fordetermining mistaken approaching/touching event. The apparatus isconfigured to perform the steps above.

The method and apparatus for determining mistaken approaching/touchingevent provided by the present application can reduce or even preventmistaken approaching/touching event being reported to a host to generateunwanted command.

The above description is only an outline of the technical schemes of thepresent invention. Preferred embodiments of the present invention areprovided below in conjunction with the attached drawings to enable onewith ordinary skill in the art to better understand said and otherobjectives, features and advantages of the present invention and to makethe present invention accordingly.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be more fully understood by reading thefollowing detailed description of the preferred embodiments, withreference made to the accompanying drawings, wherein:

FIG. 1 depicts a diagram of signal values, difference values, and dualdifference values in accordance with an embodiment of the presentapplication.

FIG. 2 depicts a diagram of an area enclosed by signal values andbaseline values in accordance with an embodiment of the presentapplication.

FIG. 3 depicts a diagram of signal values, dual difference values, andline pieces when a finger slides over conductive liquer in accordancewith an embodiment of the present application.

FIG. 4 depicts a diagram of signal values and line pieces when ghostpoints caused by multiple fingers in accordance with an embodiment ofthe present application.

FIG. 5A depicts a diagram of signal values caused by stylus tip andlarge conductive object in accordance with an embodiment of the presentapplication.

FIG. 5B depicts a diagram of signal values caused by stylus tip andlarge conductive object in accordance with an embodiment of the presentapplication.

FIG. 5C depicts a diagram of signal values caused by stylus tip andlarge conductive object in accordance with an embodiment of the presentapplication.

FIG. 6 depicts a diagram of determining palm area by line piece groupsin accordance with an embodiment of the present application.

FIG. 7 depicts a diagram of preventing mistaking multiple fingers as apalm in accordance with an embodiment of the present application.

FIG. 8 depicts a flowchart diagram of determining mistakenapproaching/touching event in accordance with an embodiment of thepresent application.

FIG. 9 depicts a diagram of a touch sensitive system in accordance withan embodiment of the present application.

FIG. 10A-D depicts flowchart diagrams of determining whether a linepiece corresponds to a stylus tip in accordance with an embodiment ofthe present application.

FIG. 11A-D depicts flowchart diagrams of determining whether a linepiece corresponds to a hovering conductive object in accordance with anembodiment of the present application.

FIG. 12 depicts a flowchart diagram for excluding line piececorresponding to palm in accordance with an embodiment of the presentinvention.

FIG. 13 depicts a flowchart diagram for determining a palm line piecegroup in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Some embodiments of the present invention are described in detailsbelow. However, in addition to the descriptions given below, the presentinvention can be applicable to other embodiments, and the scope of thepresent invention is not limited by such, rather by the scope of theclaims. Moreover, for better understanding and clarity of thedescription, some components in the drawings may not necessary be drawnto scale, in which some may be exaggerated relative to others, andirrelevant parts are omitted.

For convenience, explanations of some terms are provided below. Scope ofthe present application includes but not limits to the following simpleexplanations.

Touch Panel/Screen: A sensing layer is formed on a substrate, and itscontrol device is capable of detecting the position of at least oneconductive object approaching or touching the substrate using thesensing layer. The sensing layer may be a single-layered ormulti-layered structure.

Approaching/Touching: Approaching, approximating or touching.

External Conductive Object: It can be a part of the human body, such asa finger or a palm, or an object in connection with the human body, suchas a passive stylus. It can also be an active stylus which emits signalsto enable a touch panel to detect the position itself. It can also be agrounded testing conductive object, such as a copper cylinder. It canalso be water or conductive liquid retained on the surface of a touchpanel.

Approaching/Touching Object: An external conductive object that isapproaching or touching a substrate.

Approaching/Touching Event: An event of an external conductive objectdetected by a touch panel when the external conductive object isapproaching or touching a substrate.

Sensing Layer: It includes a plurality of (m) driving electrodesparallel to a first axis and a plurality of (n) sensing electrodesparallel a second axis. The driving electrodes and the sensingelectrodes are exposed from one another, forming m times n sensingpoints. The first axis and the second axis may be perpendicular to eachother, and m can equal to n.

Driving Electrode (First Conductive Strip): A plurality of (m)electrodes which are parallel to the first axis are used to transmitdriving signals. They can be made of transparent or opaque material suchas Indium Tin Oxide (ITO) or carbon nanotubes. It can be asingle-layered or multi-layered structure.

Sensing Electrode (Second Conductive Strip): Electrodes used fordetecting capacitive signals. It can be made of transparent or opaquematerial such as Indium Tin Oxide (ITO) or carbon nanotubes. It can be asingle-layered or multi-layered structure.

One-dimensional Sensing Information: A plurality of sensing informationcorresponding to a first axis or a second axis. It may indicate acollection of signal values of m sensing points of m driving electrodescorresponding to a single sensing electrode. It may also indicate acollection of signal values of n sensing points of n sensing electrodescorresponding to a single driving electrode. In other words,one-dimensional sensing information may include signal values of msensing points, or signal values of n sensing points. One-dimensionalsensing information may also include single difference values or dualdifference values of m/n sensing points.

Two-dimensional Sensing Information: Sensing information formed bycombining a plurality of one-dimensional sensing information. It canalso be called an image.

Baseline or Stray: A signal value corresponding to a specific workingfrequency.

Signal Value: It can be a signal directly detected by a sensingelectrode or a signal value restored from a single difference value or adual difference value, although these two value may not be the same,they are interchangeable in some embodiments.

Single Difference Value (or simply Difference): The difference insignals values between adjacent sensing points.

Dual Difference Value: The difference between adjacent differencevalues.

Line Piece: All or a continuous part of one-dimensional sensinginformation.

Line Piece Group: A plurality of line pieces corresponding to adjacentone-dimensional sensing information, and there is at least one pair ofneighboring sensing points on adjacent axes.

Ghost Point: A point or region corresponding to an unwanted capacitivesensing.

There are three processes in the operations of a touch panel/screen. Oneis a full screen driving detection process, in which the existence of atleast one approaching/touching object can be determined bysimultaneously providing driving signals to all of the drivingelectrodes. The second one is an external noise detection process, inwhich the supplying of driving signals to all of the driving electrodesis stopped to determine if an external electromagnetic interference issevere. The third one is a touch point reporting process, in whichdriving signal is sequentially provided to each of the drivingelectrodes, and then touch points and/or related information arereported to other software or hardware based on signal values detectedor read by each of the sensing electrodes.

In an embodiment, the order in which the above three processes areexecuted is that the full screen driving detection process is firstexecuted to make sure there is no external conductive object on thetouch panel/screen, then the external noise detection process isexecuted to make sure the external electromagnetic interference is notsevere or to set a new working frequency of driving signal, and finallythe touch point reporting process is executed.

In one embodiment, after the touch point reporting process, the aboveprocesses are iterated.

In another embodiment, after several iterations of the touch pointreporting process are performed, the external noise detection process isexecuted once, and then several iterations of the touch point reportingprocess are again followed by one external noise detection process.After the external noise detection process is performed several times,the full screen driving detection process is then executed.

One with ordinary skill in the art can appreciate that there areinfinite number of combinations of the executions of the above threeprocesses, and the present invention is not limited to a particularcombination. The order of executions can be determined in advance, orcan be altered on the fly depending on the situations encountered, orthe execution of a specific process is decided on the fly.

In general, the objectives of the touch point reporting process are todetect a pen touch and/or a fingertip approaching/touching the touchpanel/screen, and to eliminate palms and water (a combinationalrepresentation of conductive liquid, referred to as water hereinafter)or unwanted capacitive sensing. The touch point reporting process mayfurther include and be divided into the following steps: scanning ordetecting all sensing points; making adjustment based on the electricalcharacteristics of the sensing electrodes and the curvature of thesubstrate; determining at least one line piece corresponding to each ofthe above objects; examining every line piece to eliminate water andghost points; combining eligible line piece(s) into a line piece groupto eliminate palms; positioning a pen touch and/or fingertip(s);tracking positions or tracing; and reporting the position(s). Althoughthe touch point reporting process can include every one of the abovesteps, but not every step is necessary, and some may be bypassed.

In general, a processing module of a touch panel/screen can obtain mlines of one-dimensional (1D) sensing information detected by everysensing electrode. Each line of 1D sensing information includes n piecesof information corresponding to the sensing points of respective drivingelectrodes. The processing module may obtain signal values directly, orobtain difference values directly. When signal values are obtained,difference values of these signal values can be calculated. Whendifference values are obtained, signal values can be derived through thebaseline. Then, dual difference values can be further calculatedregardless whether 1D sensing information of signal values or differencevalues are obtained.

Referring to FIG. 1, the topmost curve 14 indicates signal values; themiddle curve 15 indicates difference values; and the bottommost curve 16indicates dual difference values.

In optional steps, owing to the electrical characteristics of thesensing electrodes, signal value detected by each sensing point may havesome deviations that can be adjusted. In addition, since the substratemay be bent as a result of an approaching/touching event, the substrateitself may be deformed. Thus, the effect of the deformation of thesubstrate can also be adjusted.

The step of determining a line piece using an 1D sensing information caninclude finding the range of the line piece using dual differencevalues, difference values and/or signal values. Once the dual differencevalues are obtained, there are several ways to extract the line pieces.

In one embodiment, a “relative high point” higher than a dual differencethreshold can be first determined. Then, a “relative low point” is foundretrospectively (which is called a first point or a preceding point),and another “relative low point” is found prospectively (which is calleda second point or a following point); the range of this line piece isfrom the first point to the second point. For example, there are 1Dsensing information of n sensing points. A relative high point is foundat the 20^(th) point, a relative low point found retrospectively is atthe 15^(th) point, and another relative low point found retrospectivelyis at the 25^(th) point; the range of this line piece is from the15^(th) point to the 25^(th) point, and the length of the line piece is11.

However, in some examples, a relative low point cannot be foundretrospectively or prospectively within a certain range. When thishappens, a certain retrospective or prospective distance is defined asthe range of the line piece. For example, the above distance is set to5. Thus, when a relative low point cannot be found prospectively from arelative high point (e.g. the 20^(th) point), then the 25^(th) point isdefined as the second point, and the range of the line piece is from the15^(th) point to the 25^(th) point, and the length of the line piece is11, and vice versa.

The above embodiment is suitable for extracting a line piece having avalue higher than the dual difference threshold. However, someapproaching/touching events may occur without generating a single dualdifference value that is higher than the dual difference threshold,instead a flatter curve of dual difference values is generated. Forexample, when the tip of a slim stylus or pencil touches the panel, asingle dual difference value that is higher than the dual differencethreshold will not be generated. Therefore, if such a type ofapproaching/touch object is to be detected, then the following methodfor extracting a line piece can be adopted.

First, two contiguous positive dual difference values are found andadded together to compare with the dual difference threshold. If the sumis higher than the dual difference threshold, these are the relativehigh points. Then, similarly, a relative low point (called a first orpreceding point) is found retrospectively. After that, a relative lowpoint (called a second or following point) is found prospectively. Therange of this line piece is from the first point to the second point.Similarly, when a relative low point cannot be found retro- orprospectively, then a certain retrospective or prospective distance isdefined as the range of the line piece.

For example, assuming the dual difference threshold is 5, and a seriesof dual difference values is [0, 0, 0, −1, −3, −1, 1, 3, 3, 1, −1, −3,−1, 0, 0, 0]. In the above series, the first two positive dualdifference values are 1 and 3, but their sum is less than the dualdifference threshold. Next, two contiguous 3s are found prospectively.Since their sum is 6, which is greater than the dual differencethreshold, these two values are regarded as the relative high points.Then, the first point and the second point are found retrospectively andprospectively.

It should be noted that the second method that compares the sum of twopositive dual difference values with the threshold is also applicable tothe scenario where there is only a single value that is greater than thethreshold.

Once all line pieces on the touch panel/screen are found, then the linepieces are examined. The examination of the line pieces may be used toeliminate water and ghost points. Herein, a combination of dualdifference values, difference value and/or signal values can be used forexamination.

When a line piece is found by using the dual difference values, thecorresponding difference values and signal values of this line piece arethen known. The area between the signal values and the baseline can becalculated. As shown in FIG. 2, when the area is below the baseline, itis called a negative. A negative area is usually caused by water or aghost point. When the area of the signal values of the line piece isnegative, then this line piece can be disregarded or ignored.

Referring now to FIG. 3, under certain circumstances, there is a bigpatch of water on the touch panel, when a fingertip crosses this patchof water, it can still be detected. Based on the above methods forfinding a line piece, three line pieces are segmented from the dualdifference values; from left to right, they are LPC1, LPC2, and LPC3,respectively.

When signal value are restored from these three line pieces, it can beseen that the area corresponding to LPC1 is negative, and so as the areacorresponding to LPC3. Only the area corresponding to the LPC2 ispositive. Therefore, at this stage, LPC1 and LPC3 are discarded orignored, leaving with only LPC2.

Referring to FIG. 4, under some circumstances, ghost points may begenerated. For example, there are four approaching/touching eventsoccurring simultaneously in the touch area. Since current will flow fromone approaching/touching event to the other approaching/touching event,such as from one finger to another finger of the same palm, and thenback to a sensing electrode, a ghost point will be generated. Theseghost points will be detected in the dual difference values, wherein twoapproaching/touching events and two ghost points belong to the sameaxis.

In the step of line piece extraction, apart from LPC1 and LPC5corresponding to two respective approaching/touching events, there aretwo other line pieces LPC2 and LPC4 corresponding to two ghost points.However, between the two ghost points, another line piece LPC3 isdetected. When determining the area of the signal value of each linepiece, it is found that the areas of the signal values of the linepieces LPC1 and LPC5 are positive, while the rest (LPC2, LPC3 and LPC4)are negative. Therefore, LPC2, LPC3 and LPC4 can be discarded orignored, leaving only LPC1 and LPC5.

Referring to FIG. 5A, under some circumstances, there may be unwantedapproaching/touching events. On the right-hand side of the diagram, itshows the touch of the tip of a pen, which has a very small touch areaand the amount of signal variation it causes is not significant. On theleft-hand side of the diagram, it shows a large conductive object, forexample, a copper rod with a very good conductivity coefficient. Whenthe copper rod is still some distance away from the touch panel/screen,it has already started to influence the sensing electrode. These twoapproaching/touching events will be found during line piece extraction,but the touch panel should not report a touch point for theapproaching/touching event on the left-hand side of the diagram.

Thus, when examining their signal values, the slopes of the line piecesat the edges as well as the areas, which may be represented by thelength, of the line pieces can be examined. The area of the tip of thepen (Area 2) is smaller, but the slope of the edge of this line piece(Slope 2) is larger. The area of the left-hand side approaching/touchingevent (Area 1A) is larger, but the slope of the edge of this line piece(Slope 1A) is smaller. Therefore, the line piece corresponding to theleft-hand side approaching/touching event can be removed using both theslope and the area to filter out the unwanted approaching/touchingevent.

Referring now to FIG. 5B, comparing with FIG. 5A, the externalconductive object gets closer to the touch panel. Similarly, the leftapproaching/touching event needs to be eliminated by the touch panel.Thus, by using the same examination described in FIG. 5A, the slopes atthe edges as well as the areas, which may be represented by the length,of the line pieces are examined. The area of the stylus tip (Area 2) issmaller, but the slope of the edge of this line piece (Slope 2) islarger. The area of the left-hand side approaching/touching event (Area1B) is larger, but the slope of the edge of this line piece (Slope 1B)is smaller. Although the area 1B and the signal values shown in FIG. 5Bis larger than the area 1A and the signal values shown in FIG. 5A, theslopes (Slope 1A and Slope 1B) at the edges of the line pieces aresmaller than the slope (Slope 2) of the line piece caused by the stylustip. Thus, by examining the slope and the area, undesiredapproaching/touching event are eliminated by discarding the line piececorresponding to the left approaching/touching event.

Referring now to FIG. 5C, comparing with FIGS. 5A and 5B, the externalconductive object already contacts the touch panel. Therefore the signalvalues corresponding to the conductive object is larger than the signalvalues corresponding to the stylus tip. Hence, the slope (Slope 1C) atthe edges of the corresponding line piece is larger than the slopes(Slope 1A and Slope 1B) at the edges of the corresponding line pieces.Besides, the area (Area 1C) is also larger than the areas (Area 1A andArea 1B). Thus, although the left approaching/touching events shown inFIGS. 5A and 5B are eliminated, the left event shown in FIG. 5C wouldnot be discarded by examining the slope and the area.

After all line pieces are examined, and after some line pieces resultingfrom water, ghost points or unwanted approaching/touching events arediscarded or ignored, the line pieces are grouped into line piece groupsin order to find the centroids of the approaching/touching events, andremove the portion(s) touched by one or more palms.

Referring to FIG. 6, after all the line pieces are found, line piecesthat are adjacent to each other in the vertical direction are groupedinto one line piece group. In FIG. 6, there are four line piece groups,wherein Group 4 is an approaching/touching event caused by a palm. Group2 and Group 3 are approaching/touching events caused by touches offingers that are not intended to operate on the touch panel, so theyshould be considered as part of the palm. Only Group 1 is a realapproaching/touching event caused by a fingertip or the tip of a penthat is operating on the touch panel. In other words, the touchpanel/screen should classify Group 2, Group 3 and Group 4 as part of thepalm, and only report a touch point for Group 1.

In an embodiment, a line piece is considered as part of the palm if itsatisfies one or a combination of the following conditions. ConditionOne: when a signal value of a line piece in a line piece group is higherthan a palm signal threshold. Condition Two: when the length of a linepiece in a line piece group is larger than a palm length threshold.Condition Three: when the number of line pieces in a line piece group islarger than a palm line piece quantity threshold. The palm lengththreshold may or may not be equal to the palm line piece quantitythreshold.

As long as one line piece group is classified as a palm line piecegroup, a step of combining other line piece groups can be performed. InFIG. 6, every line piece in Group 4 can be extended in both thehorizontal and vertical directions. After extending a certain amount ofhorizontal distance, if another line piece group is met, then thetouched line piece group is also considered as part of the palm linepiece group. For example, Group 2 and Group 3 are both included in thehorizontal extension range of Group 4, so these line piece groups areclassified as the palm line piece group. However, Group 1 is obviouslytoo far from Group 4 to be included by the extension of Group 4, soGroup 1 will not classified as part of the palm line piece group.

In terms of the vertical direction, the fringe line pieces are extendedupwards and downwards; the length of an extended line piece and thelength of a fringe line piece can be the same or in proportional to eachother. For example, the length of a first extended line piece can be 80%of the length of a fringe line piece. The length of a second extendedline piece can be 80% of the length of the first extended line piece,and so on until the number of the extended line pieces has reached anupper limit, or the length of the extended line piece is less than alower limit. In FIG. 6, none of the vertically extended line pieces inGroup 4 touches other line piece groups.

It should be noted that the above extension can be limited to once only.That is, the extension is only done on Group 4 that is originallythought as a palm, and not on Group 2 and Group 3. However, the presentinvention can also include further extensions on extended line piecegroups, but their horizontal distances may be shorter than the originalhorizontal extension distance, and their numbers and proportions ofvertical extensions may be less than the originally extension number orproportion. In another embodiment, the conditions for further extensioncan be the same as the original extension.

In another embodiment, a palm rectangle can be drawn from the originalpalm line piece group. An enlarged palm rectangle can be further drawnin accordance with the above extension spirit. If another line piecegroup becomes overlapped with the enlarged palm rectangle, it will betreated as the palm line piece group.

The calculations for the method of the enlarged palm rectangle aresimpler than the previous method, but it may include more areas. If anapproaching/touching event to be reported as a touch point is in therange of the enlarged palm rectangle, its corresponding line piece groupis usually ignored. Thus, in the case where computational resources arenot a concern, the previous extension method is better.

During handwriting, since the palm and the fingertip keeps moving, theirtouch areas may change rapidly. Sometimes, the portion touched by a palmmay be divided into many separate smaller regions and cannot be detectedas a palm. Thus, when a palm line piece group is being detected by adetection scan, a palm flag and/or a timestamp can be set.

During the period in which the palm flag is set, three of the aboveconditions can be relaxed. For example, the palm signal threshold can bereduced; the palm length threshold can be shortened; and the palm linepiece quantity threshold can be reduced. As a result, there is a higherprobability of determining a line piece as a palm line piece group. Inan embodiment, the above relaxed region can be limited to be within anenlarged palm rectangle or an enlarged palm shape. Only when theenlarged palm rectangle or shape overlaps with a line piece group, thethree conditions are relaxed. When no palm line piece group is detected,the timestamp can be checked to see if it is expired. When the timestamphas already exceeded a threshold, the palm flag can be cleared.

The present invention is not limited to the above method for setting thepalm flag and/or timestamp. As long as a palm is being determined, theconditions for determining as a palm can be relaxed.

In some circumstances, an approaching/touching event is very close, soit requires a special method for dismantling a line piece group.Referring to FIG. 7, when four fingers are used at the same time,according to the above three conditions, the line pieces correspondingto these four fingertips will be combined into one line piece group.Since the number of line pieces in this line piece group is greater thanthe palm line piece quantity threshold, so they will be considered as apalm line piece group and thus discarded.

In order to prevent this from happening, the palm line piece group isanalyzed. When its total area (i.e. the total length of the line pieces)is smaller than its corresponding normal palm area, then a dismantlingstep is performed. Alternatively, when the length of each line piece inthe palm line piece group varies between long and short, the dismantlingstep can also be performed. During dismantling, it can be seen that thesignal values between each fingertip are very small, so it can bedismantled into four line piece groups; each corresponds to a fingertip.Since the original line piece group is broken down into four linepieces, it will no longer be considered as a palm line piece group.Therefore, the approaching/touching events corresponding to the fourline piece groups will be reported as touch points.

Another scenario that requires special treatment is the line piece groupfor the tip of a pen. In some embodiments, for example, when the spacingbetween sensing electrodes is approximately 4 mm, and the diameter ofthe tip of the pen is about 1.5-2 mm, there are only two possibility forthe corresponding line piece(s). There is a higher probability that itwill correspond to a single short line piece, and there is a lowerprobability that it will correspond to a line piece group composed oftwo adjacent line piece that are about the same length, but theirlengths are relatively short as well.

Thus, when a single line piece is detected, it is determined whether itis the tip of a pen. It has already been mentioned earlier that acondition for determining the tip of a pen may include determining theslope of the signal value of the line piece at the edge. When the tip ofa pen is determined, a corresponding pen tip flag and/or a timestamp ofthe pen tip can then be set.

Assuming in the next scanning detection, a pen tip having a line piecegroup with similar characteristics is detected, it is determined whetherthe above pen tip flag has been set. If so, then the line piece group isdetermined to be a pen tip, and must be reported as a touch point.Otherwise, this line piece group is ignored. Since when a pen tip firstapproaches/touches a touch panel/screen, there is only a lowerprobability that it will appear as a line piece group. Once it startsmoving, the appearance of a single line piece is almost guaranteed, soit will not affect the experience of the user much.

The timestamp can be used for comparison. After the trace of the tip ofthe pen has disappeared for a period of time, then the pen tip flag canbe cleared. It should be noted that if a plurality of pen tips areallowed to approach/touch the touch panel/screen at the same time, thenthe above pen tip flag will need to correspond to the trace of aparticular pen tip.

After the touch point reporting process, positioning is performed basedon the line piece groups; positions are tracked or traced; and thepositions are reported.

Please refer to FIG. 8, which illustrates a flowchart diagram of methodfor determining mistaken approaching/touching event in accordance withan embodiment of the present invention. As shown in FIG. 8, except forthose consequential steps, the present invention does not limit theexecution order of the steps. And additional step could be inserted intotwo steps. Besides, embodiments shown in FIGS. 2-4 are incorporated intoreferences.

In one embodiment, the flow may begin at step 810, receiving 1D sensinginformation including signal values and calculating 1D sensinginformation including difference values according to the received 1Dsensing information including signal values. Next, step 820 isperformed.

In another embodiment, the flow may begin at step 820, calculating 1Dsensing information including dual difference values according to 1Dsensing information including difference values. Next, step 830 isperformed.

In an alternative embodiment, the flow may begin at step 830,determining a line piece according to 1D sensing information includingdual difference values. Next, step 840 is performed. The paragraphsabove already mentioned how to determine line piece, thus no furtherdescription is elaborated.

It is worth noted that chip or apparatus embodying the method embodimentshown in FIG. 8 may receive signal values, difference values and/or dualdifference values while receiving 1D sensing information. The presentinvention does not limit to receive a specific type of value as long asline pieces could be determined accordingly.

Step 840 is performed for gathering one or more signal valuescorresponding to determined line pieces. As indicated above, the presentinvention does not limit to receive a specific type of value. However,in step 840, signal values corresponding to determined line pieces haveto be acquired. For example, if dual difference values are received bychip or apparatus realizing the method embodiment shown in FIG. 8,corresponding difference values could be calculated first, thencorresponding signal values could be calculated in consequence. In casedifference values are received by chip or apparatus practicing themethod embodiment shown in FIG. 8, corresponding signal values could becalculated accordingly. If what chip or apparatus receives are signalvalues, those corresponding to determined line pieces could be extractedaccordingly.

Step 850 is performed for calculating a sum of differences betweensignal values and corresponding baselines. In other words, an arearepresenting an enclosure between signal values and baselines is thesum.

Next, step 860 is performed for determining whether the sum or the areais less than or equals to zero. Alternatively, it is used fordetermining whether the sum or the area is less than zero. If so, theflow goes to step 870. It is determined that the line piece is relatedto a mistaken approaching/touching event, which is probably caused byghost point or water spot. In one instance, the 1D sensing informationcorresponding to the line piece may be discarded or ignored. There is noneed for further calculation with regard to the mistaken event. If theresult of step 860 is negative, the flow goes to step 880. Theapproaching/touching event corresponding to the line piece would becalculated.

Please refer to FIG. 9, which depicts a touch sensitive system 900 inaccordance with an embodiment of the present invention. The system 900comprises at least one approaching/touching object 910, a touch panel920, a touch sensitive processing apparatus 930, and a host 940. In theembodiment, the touch panel 920 is formed on top of a substrate. Thetouch panel 920 may be a touch screen. The present invention does notlimit forms of the touch panel 920.

In one embodiment, a touch sensitive area of the touch panel 920comprises a plurality of first electrodes 921 and a plurality of secondelectrodes 922. Multiple sensing points are formed in the intersectionsof these two electrodes. The first electrodes 921 and the secondelectrodes 922 are connected to the touch sensitive processing apparatus930. In a mutual capacitance detecting mode, the first electrodes 921could be first conductive strips or driving electrodes, the secondelectrodes 922 could be second conductive strips or sensing electrodes.The touch sensitive processing apparatus 930 may provide driving voltage(voltage of driving signals) to those first electrodes 921 and measuresignal variations on those second electrodes 922 to determine whetherexternal conductive object approaches or touches the touch panel 920.People with ordinary skill in the art can understand that the touchsensitive processing apparatus 930 can detect approaching/touchingobject and event according to mutual capacitance or self-capacitancemechanisms. The principles of the mechanisms are not elaborated here.

FIG. 9 also shows the host 940 which may be a central processing unitexecuting operating system, a core processor of an embedded system, orany other form of computer. In one embodiment, the touch sensitivesystem 900 may be a tablet computer. The host 940 may be a CPU executingoperating system of the tablet computer. For example, the tablet runs onAndroid OS and the host 940 is an ARM processor which executes AndroidOS. The present invention does not limit format or forms transmittedbetween the host 940 and the touch sensitive processing apparatus 930,as long as the transmitted information is related toapproaching/touching event happened on the touch panel 920.

The touch sensitive processing apparatus 930 may be configured toexecute the method and any variants shown in FIG. 8. The touch sensitiveprocessing apparatus 930 may comprise memory or access memory which maystore software, firmware, touch sensitive signal values, differencevalues, dual difference values, and/or any other computing results orintermediate values.

In summarized, the method and apparatus for determining mistakenapproaching/touching event provided by the present invention can reduceor even prevent mistaken approaching/touching event is reported to thehost and unwanted user command.

Please refer to FIG. 10A, which depicts a flowchart for determiningwhether a line piece corresponds to a stylus tip in accordance with anembodiment of the present invention. The touch sensitive processingapparatus 930 may be used to execute method flowchart and any variantsshown in FIG. 10A. The touch sensitive processing apparatus 930 maycomprise memory or access memory which may store software, firmware,touch sensitive signal values, difference values, dual differencevalues, and/or any other computing results or intermediate values. Asshown in FIG. 10A, except for those consequential steps, the presentinvention does not limit the execution order of the steps. Andadditional step could be inserted into two steps. Besides, embodimentsshown in FIGS. 5A, 5B, 5C, and 8 are incorporated into references.

In one embodiment, as shown in steps 810 through 840 of FIG. 8, touchsensitive signal values corresponding to at least one line piece aregathered. Next, step 1010 is executed for determining a first slope atedge of the line piece. The first slope may be slope of left edge of theline piece or right edge of the line piece. In one instance, assumingthe first slope is the slope of left edge, it may look for a firstrelative high point from the most left of the line piece to right. Thenthe first slope in between the left edge to the first relative highpoint could be calculated accordingly. Alternatively, assuming the firstslope is the slope of right edge, it may look for the first relativehigh point from the rightest of the line piece to left. Then the firstslope in between the right edge to the first relative high point couldbe calculated accordingly. Besides, alternative slope calculating methodmay be used. For example, a slope of a certain range of the line pieceedge may be taken as the first slope.

Once the first slope is calculated, step 1020 could be performed inconsequence for determining whether the first slope is larger than aslope threshold value. If the result is negative, flow goes to step1050. It is determined that the line piece is not corresponding to astylus tip, or any other small area approaching/touching event caused byexternal conductive object. If the result is positive, flow may go tooptional step 1030 or step 1040. It is determined that the line piece iscorresponding to a stylus tip or any other small areaapproaching/touching event caused by external conductive object.

In optional step 1030, it is determined that whether length of the linepiece is smaller than a length threshold. If the result is negative, itis determined that the line piece is not corresponding to a stylus tipor any other small area approaching/touching event caused by externalconductive object. Otherwise, if the result is yes, flow goes to step1040. It is determined that the line piece is corresponding to a stylustip or any other small area approaching/touching event caused byexternal conductive object.

Please refer to FIG. 10B, which depicts a flowchart for determiningwhether a line piece corresponds to a stylus tip in accordance with anembodiment of the present invention. Comparing with embodiment shown inFIG. 10A, the embodiment shown in FIG. 10B reuses the steps 1040, 1040,and 1050. In the initial step 1015, a second slope is calculated inadditional to calculating the first slope. If the first slope representsslope of the left edge of the line piece, the second slope representsslope of the right edge of the line piece. Otherwise, if the first sloperepresents slope of the right edge of the line piece, the second sloperepresents slope of the left edge of the line piece.

Next, in step 1025, it is determined whether both the first and thesecond slopes are larger than the slope threshold. If the result is no,it is determined that the line piece is not corresponding to a stylustip or any other small area approaching/touching event caused byexternal conductive object. Otherwise, if the result is yes, flow may goto optional step 1030 or directly to step 1040. It is determined thatthe line piece is corresponding to a stylus tip or any other small areaapproaching/touching event caused by external conductive object.

Please refer to FIG. 10C, which depicts a flowchart for determiningwhether a line piece corresponds to a stylus tip in accordance with anembodiment of the present invention. Comparing with embodiment shown inFIG. 10A, the embodiment shown in FIG. 10B reuses all of the steps butchanges their execution sequence. Initially, step 1030 is performed. Ifthe result is negative, flow goes to step 1050. Otherwise, if the resultis positive, flow may go to optional step 1010 or step 1040. After theoptional step 1010 is executed, step 1020 follows. If the result isnegative, flow goes to step 1050. Otherwise, if the result is positive,flow goes to step 1040.

Please refer to FIG. 10D, which depicts a flowchart for determiningwhether a line piece corresponds to a stylus tip in accordance with anembodiment of the present invention. Comparing with embodiment shown inFIG. 10C, the embodiment shown in FIG. 10D substitutes the steps 1010and 1020 with the steps 1015 and 1025, respectively. At the beginning,step 1030 is performed. If the result is negative, flow goes to 1050.Otherwise, if the result is positive, flow may go to optional step 1015or step 1040. After the optional step 1015 is executed, step 1025follows. If the result is negative, flow goes to step 1050. Otherwise,if the result is positive, flow goes to step 1040.

Please refer to FIG. 11A, which depicts a flowchart for determiningwhether a line piece corresponds to a hovering conductive object inaccordance with an embodiment of the present invention. The touchsensitive processing apparatus 930 as shown in FIG. 9 may be used toexecute method flowchart and any variants shown in FIG. 11A. The touchsensitive processing apparatus 930 may comprise memory or access memorywhich may store software, firmware, touch sensitive signal values,difference values, dual difference values, and/or any other computingresults or intermediate values. As shown in FIG. 11A, except for thoseconsequential steps, the present invention does not limit the executionorder of the steps. And additional step could be inserted into twosteps. Besides, embodiments shown in FIGS. 5A, 5B, 5C, 8, 10A, 10B, 10C,and 10D are incorporated into references.

In one embodiment, as shown in steps 810 through 840 of FIG. 8, touchsensitive signal values corresponding to at least one line piece aregathered. Next, step 1110 is executed for determining a first slope atedge of the line piece. The first slope may be slope of left edge of theline piece or right edge of the line piece. In one instance, assumingthe first slope is the slope of left edge, it may look for a firstrelative high point from the most left of the line piece to right. Thenthe first slope in between the left edge to the first relative highpoint could be calculated accordingly. Alternatively, assuming the firstslope is the slope of right edge, it may look for the first relativehigh point from the rightest of the line piece to left. Then the firstslope in between the right edge to the first relative high point couldbe calculated accordingly. Besides, alternative slope calculating methodmay be used. For example, a slope of a certain range of the line pieceedge may be taken as the first slope

Once the first slope is calculated, flow continues to step 1120 fordetermining whether the first slope is smaller than a slope threshold.If the result is negative, flow goes to step 1150. It is determined thatthe line piece is not corresponding to a hovering conductive object. Ifthe result is positive, flow may go to optional step 1130 or directly tostep 1140. It is determined that the line piece is corresponding to ahovering conductive object.

In optional step 1130, it is configured for determining whether lengthof the line piece is smaller than a length threshold. If the result isnegative, flow goes to step 1150. It is determined that the line pieceis not corresponding to a hovering conductive object. If the result ispositive, flow goes to step 1140. It is determined that the line pieceis corresponding to a hovering conductive object.

Please refer to FIG. 11B, which depicts a flowchart for determiningwhether a line piece corresponds to a hovering conductive object inaccordance with an embodiment of the present invention. Comparing withembodiment shown in FIG. 11A, the embodiment shown in FIG. 11B reusesthe steps 1130, 1140, and 1150. In initial step 1115, a second slope iscalculated in additional to calculating a first slope. In other words,slopes at the left edge and the right edge of the line piece arecalculated. If the first slope represents slope of the left edge of theline piece, the second slope represents slope of the right edge of theline piece. Otherwise, if the first slope represents slope of the rightedge of the line piece, the second slope represents slope of the leftedge of the line piece.

Next, in step 1125, it is configured for determining whether both thefirst slope and the second slope are larger than a slope threshold. Ifthe result is negative, flow goes to step 1150. It is determined thatthe line piece is not corresponding to a hovering conductive object. Ifthe result is positive, flow goes to optional step 1130 or directly tostep 1140. It is determined that the line piece is corresponding to ahovering conductive object.

Please refer to FIG. 11C, which depicts a flowchart for determiningwhether a line piece corresponds to a hovering conductive object inaccordance with an embodiment of the present invention. Comparing withembodiment shown in FIG. 11A, the embodiment shown in FIG. 11C reusesall of the steps but changes execution consequence. Initially, step 1130is executed. If the result is negative, flow goes to step 1150.Otherwise, if the result is positive, flow goes to optional step 1110 orstep 1140. After optional step 1110 is executed, step 1120 follows. Ifthe result is negative, flow goes to step 1150. Otherwise, if the resultis positive, flow goes to step 1140.

Please refer to FIG. 11D, which depicts a flowchart for determiningwhether a line piece corresponds to a hovering conductive object inaccordance with an embodiment of the present invention. Comparing withembodiment shown in FIG. 11C, the embodiment shown in FIG. 11Dsubstitutes the steps 1110 and 1120 with the steps 1115 and 1125,respectively. At the beginning, step 1130 is performed. If the result isnegative, flow goes to optional 1150. Otherwise, if the result ispositive, flow may go to optional step 1115 or step 1140. After theoptional step 1115 is executed, step 1125 follows. If the result isnegative, flow goes to step 1150. Otherwise, if the result is positive,flow goes to step 1140.

Please refer to FIG. 12, which depicts a flowchart diagram for excludingline piece corresponding to palm in accordance with an embodiment of thepresent invention. The touch sensitive processing apparatus 930 as shownin FIG. 9 may be used to execute method flowchart and any variants shownin FIG. 12. The touch sensitive processing apparatus 930 may comprisememory or access memory which may store software, firmware, touchsensitive signal values, difference values, dual difference values,and/or any other computing results or intermediate values. As shown inFIG. 12, except for those consequential steps, the present inventiondoes not limit the execution order of the steps. And additional stepcould be inserted into two steps. Besides, embodiments shown in FIGS. 6and 8 are incorporated into references.

Before performing the embodiment as shown in FIG. 12, it may performsteps 810 through 830 of the embodiment as shown in FIG. 8. Next, instep 1210, it is supposed to form one or more line piece group by thosedetermined line pieces. As shown in FIG. 6, if adjacent line pieces haveneighboring sections or line pieces connects in vertical, these linepieces are configured to form a line piece group. After step 1210, flowmay go to optional step 1220 or directly to step 1250.

In optional step 1220, it is configured for determining whether currenttime or time of retrieving the line piece group is in a valid period ofa time stamp. In case no time stamp is set or the time is not in thevalid period of the time stamp, flow may go to optional step 1240.Otherwise, assuming that the time is in the valid period of the timestamp, flow goes to optional step 1230.

Already mentioned above, it may use one or more conditions to determinewhether a line piece group is corresponding to a palm. Indicated in theembodiment shown in FIG. 6, if a line piece group satisfies one or acombination of following conditions, it is determined that the linepiece group is corresponding to a palm. Condition One: when a signalvalue of a line piece in a line piece group is higher than a palm signalthreshold. Condition Two: when the length of a line piece in a linepiece group is larger than a palm length threshold. Condition Three:when the number of line pieces in a line piece group is larger than apalm line piece quantity threshold. The palm length threshold may or maynot be equal to the palm line piece quantity threshold.

In optional step 1230, loosening conditions; part or all of thethresholds, such as palm signal threshold, palm line piece quantitythreshold, and palm length threshold, in these conditions may be reducedor lowered. As a result, in optional step 1240, recovering conditions;the reduced thresholds in step 1230 are recovered back to normal values.The present invention does not limit the situations of reduction andrecovery.

Next, flow goes to step 1250 for determining which line piece group iscorresponding to a palm according to threshold varied in step 1230 orstep 1240 or constant threshold. Assuming that no line piece group isdetermined as a palm line piece group in step 1250, flow may stop.Otherwise, if one or more line piece group is determined as a palm linepiece group, flow may go to optional step 1260 or directly to step 1270.

Like steps 1220, 1230, and 1240, step 1260 is optional, too. In thisstep, since one or more palm line piece group is found in step 1250, thevalid period of the time stamp needs to be updated. If no time stamp isset, it may be created in step 1260. In case there is no time stamp setup in step 1210, flow may directly go to step 1250 from step 1210.

In step 1270, a procedure of extending palm line piece group isperformed. With regard to each palm line piece group, one or more of thefollowing steps may be performed. Step 1270 may comprise horizontalextension step, vertical extension step, and rectangular extension step.

The horizontal extension step is configured to extend each line piece inthe line piece group forward and backward a fixed distance or a variabledistance proportional to length of the line piece. If the line piece islonger, more distance is extended. Instead, if the line piece isshorter, less distance is extended.

The vertical extension step is configured to have one or more extensionline pieces upward and downward of fringe line pieces. Length of theseextended line pieces may be equal or in proportional to lengths ofcorresponding fringe line pieces. For example, length of the firstextended line piece may be 80% of length of corresponding fringe linepiece, length of the second extended line piece may be 80% of length ofthe first extended line piece, and so on, until number of extension linepieces hits a upper bound or length of a last extended line piece hits alower bound.

Rectangular extension step is configured to find out an enlarged palmrectangle covering the whole palm line piece group. In one instance,edges of a palm rectangle include the top and the bottom line pieces aswell as the most left and the rightest line pieces. Alternatively, theenlarged palm rectangle may cover the smallest palm rectangle.

Other line piece group covered by extended range is considered as a palmline piece group. In one embodiment, the extension is done once. Itimplies that there is no extension of the extended palm line piecegroup. In another embodiment, the extension may be performed more thanonce. It is said that extension of the extended palm line piece group isallowed. However, steps of the secondary extension may be as the same assteps of the first extension, or may be not.

At last, flow goes to step 1280 for excluding palm line piece groupdetermined in step 1250 and extended palm line piece group step 1270.

Please refer to FIG. 13, which depicts a flowchart diagram fordetermining a palm line piece group in accordance with an embodiment ofthe present invention. The touch sensitive processing apparatus 930 asshown in FIG. 9 may be used to execute method flowchart and any variantsshown in FIG. 13. The touch sensitive processing apparatus 930 maycomprise memory or access memory which may store software, firmware,touch sensitive signal values, difference values, dual differencevalues, and/or any other computing results or intermediate values. Asshown in FIG. 13, except for those consequential steps, the presentinvention does not limit the execution order of the steps. Andadditional step could be inserted into two steps. Besides, embodimentsshown in FIGS. 7 and 12 are incorporated into references.

In one embodiment, the flowchart shown in FIG. 13 may be applied in step1250 shown in FIG. 12. After one or more palm line piece group isdetermined in step 1250, the embodiment shown in FIG. 13 could befurther used to validate the palm line piece group. However, the presentinvention does not limit that the embodiment shown in FIG. 13 has to beapplied to the embodiment shown in FIG. 12.

In response to a line piece group is determined as a palm line piecegroup, flow initially goes to step 1310 for comparing a sum of lengthsof line pieces in this group with a palm line piece group lengththreshold. If the sum is larger, the flow may go to step 1340. It isdetermined that the line piece group is corresponding to a palm.Otherwise, flow may go to step 1330. It is determined that the linepiece group is not corresponding to a palm.

Alternatively, if the sum is larger than the palm line piece grouplength threshold, flow may go to step 1320 for determining whetherlengths of line pieces in this group are arranged in ascent order anddescent order for a certain times. In case they are arranged so in acertain times, flow may goes to step 1330. It is determined that theline piece group is not corresponding to a palm. Otherwise, flow goes tostep 1340, it is confirmed that the line piece group is corresponding toa palm.

In another embodiment, in case a line piece group is taken as a palmline piece group, flow initially goes to step 1320 for determiningwhether lengths of line pieces in this group are arranged in ascentorder and descent order for a certain times. In case they are arrangedso in a certain times, flow may goes to step 1330. It is determined thatthe line piece group is not corresponding to a palm. Otherwise, flowgoes to step 1340, it is confirmed that the line piece group iscorresponding to a palm.

In other embodiment, if lengths of line pieces in this group arearranged in ascent order and descent order for a certain times, flow maygoes to step 1310. If it is determined that the sum is larger than thepalm line piece group length threshold, flow may go to step 1340. It isconfirmed that the line piece group is corresponding to a palm.Otherwise, flow goes to step 1330. It is determined that the line piecegroup is not corresponding to a palm.

In summarized, step 1310 and/or step 1320 may be used for determiningwhether a palm line piece group is corresponding to a palm. In case thatthe line piece group is not corresponding to a palm, the followingprocedures may be used to break the line piece group into multiplegroups. For example, relative low points of signal values along acentral profile of the line piece group could be used to divide thegroup. Besides, line pieces with lengths shorter than a length thresholdmay be used to divide the line piece group. Furthermore, line piecesshorter than neighboring line pieces may be used to divide the linepiece group. In case two neighboring line pieces have the same lengthand shorter than other neighboring line pieces, these two line piecescould be separated into two line piece groups.

It is worth noted that if a line piece group is separated into multiplegroups, these groups would not be affected by step 1270 shown in FIG.12. In other words, even these groups are covered by extended palm linepiece group; they would not be joined into the palm line piece group.

One objective of the present application is to provide a method fordetermining mistaken approaching/touching event, comprising: gatheringone or more touch sensitive signal value corresponding to a line piece;calculating a sum of differences of each signal value and a baselinevalue; and if the sum is less than or equals to zero, determining theline piece is corresponding to a mistaken approaching/touching event.

One objective of the present application is to provide an apparatus fordetermining mistaken approaching/touching event. The apparatus isconfigured to perform the following steps: gathering one or more touchsensitive signal value corresponding to a line piece; calculating a sumof differences of each signal value and a baseline value; and if the sumis less than or equals to zero, determining the line piece iscorresponding to a mistaken approaching/touching event.

In one embodiment, the method further comprises calculating the linepiece according to 1D sensing information having dual difference values.Alternatively, the method further comprises calculating 1D sensinginformation having dual difference values according to 1D sensinginformation having difference values. Alternatively, the method furthercomprises calculating 1D sensing information having difference valuesaccording to 1D sensing information having signal values.

In one embodiment, if the sum is larger than zero, calculating theapproaching/touching event corresponding to the line piece.

One objective of the present application is to provide a method fordetermining whether a line piece is corresponding to a stylus tip,comprising: gathering multiple touch sensitive signal valuescorresponding to a line piece; calculating a first slope at edge of theline piece; determining whether the first slope is larger than a slopethreshold; and determining that the line piece is corresponding to thestylus tip if the first slope is larger than the slope threshold.

One objective of the present application is to provide an apparatus fordetermining whether a line piece is corresponding to a stylus tip. Theapparatus is configured to perform the following steps: gatheringmultiple touch sensitive signal values corresponding to a line piece;calculating a first slope at edge of the line piece; determining whetherthe first slope is larger than a slope threshold; and determining thatthe line piece is corresponding to the stylus tip if the first slope islarger than the slope threshold.

In one embodiment, the method further comprises determining whetherlength of the line piece is larger than a length threshold if the firstslope is larger than the slope threshold; and determining that the linepiece is corresponding to the stylus tip if length of the line piece isless than the length threshold.

One objective of the present application is to provide a method fordetermining whether a line piece is corresponding to a stylus tip,comprising: gathering multiple touch sensitive signal valuescorresponding to a line piece; calculating a first slope and a secondslopes at edges of the line piece; determining whether the first slopeand the second slope are larger than a slope threshold; and determiningthat the line piece is corresponding to the stylus tip if the firstslope and the second slope are larger than the slope threshold.

One objective of the present application is to provide an apparatus fordetermining whether a line piece is corresponding to a stylus tip. Theapparatus is configured to perform the following steps: gatheringmultiple touch sensitive signal values corresponding to a line piece;calculating a first slope and a second slopes at edges of the linepiece; determining whether the first slope and the second slope arelarger than a slope threshold; and determining that the line piece iscorresponding to the stylus tip if the first slope and the second slopeare larger than the slope threshold.

In one embodiment, the method further comprises determining whetherlength of the line piece is larger than a length threshold if the firstslope and the second slope are larger than the slope threshold; anddetermining that the line piece is corresponding to the stylus tip iflength of the line piece is less than the length threshold.

One objective of the present application is to provide a method fordetermining whether a line piece is corresponding to a stylus tip,comprising: determining length of the line piece is less than a lengththreshold; and determining that the line piece is corresponding to thestylus tip if length of the line piece is less than the lengththreshold.

One objective of the present application is to provide an apparatus fordetermining whether a line piece is corresponding to a stylus tip. Theapparatus is configured to perform the following steps: determininglength of the line piece is less than a length threshold; anddetermining that the line piece is corresponding to the stylus tip iflength of the line piece is less than the length threshold.

In one embodiment, if length of the line piece is less than the lengththreshold, the method further comprises: gathering multiple touchsensitive signal values corresponding to a line piece; calculating afirst slope at edge of the line piece; determining whether the firstslope is larger than a slope threshold; and determining that the linepiece is corresponding to the stylus tip if the first slope is largerthan the slope threshold.

In one embodiment, if length of the line piece is less than the lengththreshold, the method further comprises: gathering multiple touchsensitive signal values corresponding to a line piece; calculating afirst slope and a second slopes at edges of the line piece; determiningwhether the first slope and the second slope are larger than a slopethreshold; and determining that the line piece is corresponding to thestylus tip if the first slope and the second slope are larger than theslope threshold.

One objective of the present application is to provide a method fordetermining whether a line piece is corresponding to a hoveringconductive object, comprising: gathering multiple touch sensitive signalvalues corresponding to a line piece; calculating a first slope at edgeof the line piece; determining whether the first slope is less than aslope threshold; and determining that the line piece is corresponding tothe hovering conductive object if the first slope is less than the slopethreshold.

One objective of the present application is to provide an apparatus fordetermining whether a line piece is corresponding to a hoveringconductive object. The apparatus is configured to perform the followingsteps: gathering multiple touch sensitive signal values corresponding toa line piece; calculating a first slope at edge of the line piece;determining whether the first slope is less than a slope threshold; anddetermining that the line piece is corresponding to the hoveringconductive object if the first slope is less than the slope threshold.

In one embodiment, the method further comprises determining whetherlength of the line piece is less than a length threshold if the firstslope is less than the slope threshold; and determining that the linepiece is corresponding to the hovering conductive object if length ofthe line piece is less than the length threshold.

One objective of the present application is to provide a method fordetermining whether a line piece is corresponding to a hoveringconductive object, comprising: gathering multiple touch sensitive signalvalues corresponding to a line piece; calculating a first slope and asecond slope at edges of the line piece; determining whether the firstslope and the second slope are less than a slope threshold; anddetermining that the line piece is corresponding to the hoveringconductive object if the first slope and the second slope are less thanthe slope threshold.

One objective of the present application is to provide an apparatus fordetermining whether a line piece is corresponding to a hoveringconductive object. The apparatus is configured to perform the followingsteps: gathering multiple touch sensitive signal values corresponding toa line piece; calculating a first slope and a second slope at edges ofthe line piece; determining whether the first slope and the second slopeare less than a slope threshold; and determining that the line piece iscorresponding to the hovering conductive object if the first slope andthe second slope are less than the slope threshold.

In one embodiment, the method further comprises determining whetherlength of the line piece is less than a length threshold if the firstslope and the second slope are less than the slope threshold; anddetermining that the line piece is corresponding to the hoveringconductive object if length of the line piece is less than the lengththreshold.

One objective of the present application is to provide a method fordetermining whether a line piece is corresponding to a hoveringconductive object, comprising: determining whether length of the linepiece is less than a length threshold; and determining that the linepiece is corresponding to the hovering conductive object if length ofthe line piece is less than the length threshold.

One objective of the present application is to provide an apparatus fordetermining whether a line piece is corresponding to a hoveringconductive object. The apparatus is configured to perform the followingsteps: determining whether length of the line piece is less than alength threshold; and determining that the line piece is correspondingto the hovering conductive object if length of the line piece is lessthan the length threshold.

In one embodiment, if length of the line piece is less than the lengththreshold, the method further comprises: gathering multiple touchsensitive signal values corresponding to a line piece; calculating afirst slope at edge of the line piece; determining whether the firstslope is less than a slope threshold; and determining that the linepiece is corresponding to the stylus tip if the first slope is less thanthe slope threshold.

In one embodiment, if length of the line piece is less than the lengththreshold, the method further comprises: gathering multiple touchsensitive signal values corresponding to a line piece; calculating afirst slope and a second slopes at edges of the line piece; determiningwhether the first slope and the second slope are less than a slopethreshold; and determining that the line piece is corresponding to thestylus tip if the first slope and the second slope are less than theslope threshold.

One objective of the present application is to provide an apparatus forexcluding a line piece group corresponding to a palm, comprising:gathering multiple line piece groups; determining whether one or morepalm line piece groups exist among the multiple line piece groups;extending the one or more palm line piece groups; and excluding theextended palm line piece group.

One objective of the present application is to provide an apparatus forexcluding a line piece group corresponding to a palm. The apparatus isconfigured to perform the following steps: gathering multiple line piecegroups; determining whether one or more palm line piece groups existamong the multiple line piece groups; extending the one or more palmline piece groups; and excluding the extended palm line piece group.

In one embodiment, the method further comprises: determining whether thetime of acquiring the multiple line piece groups is in a valid period ofa time stamp; loosening condition for determining the palm line piecegroup if the time is determined in the valid period of the time stamp;recovering condition for determining the palm line piece group if thetime is not determined in the valid period of the time stamp.Alternatively, the method further comprises updating the valid period ofthe time stamp if the palm line piece group exists.

In one embodiment, the step of determining whether one or more palm linepiece groups exist among the multiple line piece groups furthercomprises: taking a line piece group is a palm line piece group if asignal value of a line piece of the line piece group is larger than apalm signal threshold.

In one embodiment, the step of determining whether one or more palm linepiece groups exist among the multiple line piece groups furthercomprises: taking a line piece group is a palm line piece group iflength of a line piece of the line piece group is larger than a palmlength threshold.

In one embodiment, the step of determining whether one or more palm linepiece groups exist among the multiple line piece groups furthercomprises: taking a line piece group is a palm line piece group ifquantity of line pieces of the line piece group is larger than a palmline piece quantity threshold.

In one embodiment, the step of loosening condition for determining thepalm line piece group comprises reducing one or any combination of thefollowing thresholds: a palm signal threshold; a palm length threshold;and a palm line piece quantity threshold. Alternatively, the step ofrecovering condition for determining the palm line piece group comprisesrecovering one or any combination of the following thresholds: a palmsignal threshold; a palm length threshold; and a palm line piecequantity threshold.

In one embodiment, the step of extending the one or more palm line piecegroups further comprises one or any combination of the following steps:a horizontal extension step; a vertical extension step; and arectangular extension step.

In one embodiment, the horizontal extension step is configured to extendeach line piece in the line piece group forward and backward a fixeddistance or a variable distance. Alternatively, the variable distance isproportional to length of the line piece.

In one embodiment, the vertical extension step is configured to have oneor more extension line pieces upward and downward of fringe line pieces,length of these extended line pieces may be equal or in proportional tolengths of corresponding fringe line pieces. Alternatively, length ofextension line piece is proportional to length of corresponding fringeline piece and number of extension line pieces.

In one embodiment, the rectangular extension step is configured to findout an enlarged palm rectangle covering the whole palm line piece group.Alternatively, the enlarged palm rectangle covers a smallest palmrectangle.

In one embodiment, the method further comprises determining whether thepalm line piece group needs to be divided before extending the palm linepiece group. Alternatively, the step of determining whether the palmline piece group needs to be divided comprises one or any combination ofthe following conditions: determining whether a length sum of linepieces of the line piece group is larger than a palm line piece grouplength threshold; and determining whether lengths of line pieces in theline piece group are arranged in ascent order and descent order for acertain times.

In one embodiment, the method further comprises searching for relativelow points of signal values along a central profile of the line piecegroup; and dividing the line piece group by the relative low points ifit is determined that the palm line piece group needs to be divided. Inone embodiment, the method further comprises searching for line pieceswith lengths shorter than a length threshold; and dividing the linepiece group by the line pieces with lengths shorter than the lengththreshold if it is determined that the palm line piece group needs to bedivided. In one embodiment, the method further comprises searching forline pieces shorter than neighboring line pieces; and dividing the linepiece group by the line pieces shorter than neighboring line pieces ifit is determined that the palm line piece group needs to be divided.Alternatively, the method further comprises searching for twoneighboring line pieces having the same length and shorter than otherneighboring line pieces; and dividing the line piece group by the linepieces having the same length if it is determined that the palm linepiece group needs to be divided.

In one embodiment, if a line piece group is divided into multiple secondline piece groups, the second line piece groups are not part of theextended palm line piece group.

One objective of the present application is to provide a method fordetermining whether a palm line piece group needs to be divided,comprising one or any combination of the following steps: determiningwhether a length sum of line pieces of the line piece group is largerthan a palm line piece group length threshold; and determining whetherlengths of line pieces in the line piece group are arranged in ascentorder and descent order for a certain times.

One objective of the present application is to provide an apparatus fordetermining whether a palm line piece group needs to be divided. Theapparatus is configured to perform one or any combination of thefollowing steps: determining whether a length sum of line pieces of theline piece group is larger than a palm line piece group lengththreshold; and determining whether lengths of line pieces in the linepiece group are arranged in ascent order and descent order for a certaintimes.

In one embodiment, the method further comprises searching for relativelow points of signal values along a central profile of the line piecegroup; and dividing the line piece group by the relative low points ifit is determined that the palm line piece group needs to be divided. Inone embodiment, the method further comprises searching for line pieceswith lengths shorter than a length threshold; and dividing the linepiece group by the line pieces with lengths shorter than the lengththreshold if it is determined that the palm line piece group needs to bedivided. In one embodiment, the method further comprises searching forline pieces shorter than neighboring line pieces; and dividing the linepiece group by the line pieces shorter than neighboring line pieces ifit is determined that the palm line piece group needs to be divided.Alternatively, the method further comprises searching for twoneighboring line pieces having the same length and shorter than otherneighboring line pieces; and dividing the line piece group by the linepieces having the same length if it is determined that the palm linepiece group needs to be divided.

The above embodiments are only used to illustrate the principles of thepresent invention, and they should not be construed as to limit thepresent invention in any way. The above embodiments can be modified bythose with ordinary skill in the art without departing from the scope ofthe present invention as defined in the following appended claims.

What is claimed is:
 1. A method for excluding a line piece groupcorresponding to a palm, comprising: gathering multiple line piecegroups; determining whether one or more palm line piece groups existamong the multiple line piece groups; extending the one or more palmline piece groups; and excluding the extended palm line piece group. 2.The method of claim 1, further comprises: determining whether the timeof acquiring the multiple line piece groups is in a valid period of atime stamp; loosening condition for determining the palm line piecegroup if the time is determined in the valid period of the time stamp;and recovering condition for determining the palm line piece group ifthe time is not determined in the valid period of the time stamp.
 3. Themethod of claim 2, further comprises updating the valid period of thetime stamp if the palm line piece group exists.
 4. The method of claim1, wherein the step of determining whether one or more palm line piecegroups exist among the multiple line piece groups further comprises:taking a line piece group is a palm line piece group if a signal valueof a line piece of the line piece group is larger than a palm signalthreshold.
 5. The method of claim 1, wherein the step of determiningwhether one or more palm line piece groups exist among the multiple linepiece groups further comprises: taking a line piece group is a palm linepiece group if a length of a line piece of the line piece group islarger than a palm length threshold.
 6. The method of claim 1, whereinthe step of determining whether one or more palm line piece groups existamong the multiple line piece groups further comprises: taking a linepiece group is a palm line piece group if quantity of line pieces of theline piece group is larger than a palm line piece quantity threshold. 7.The method of claim 2, wherein the step of loosening condition fordetermining the palm line piece group comprises reducing one or anycombination of the following thresholds: a palm signal threshold; a palmlength threshold; and a palm line piece quantity threshold.
 8. Themethod of claim 2, wherein the step of recovering condition fordetermining the palm line piece group comprises recovering one or anycombination of the following thresholds: a palm signal threshold; a palmlength threshold; and a palm line piece quantity threshold.
 9. Themethod of claim 1, wherein the step of extending the one or more palmline piece groups further comprises one or any combination of thefollowing steps: a horizontal extension step; a vertical extension step;and a rectangular extension step.
 10. The method of claim 9, wherein thehorizontal extension step is configured to extend each line piece in theline piece group forward and backward a fixed distance or a variabledistance.
 11. The method of claim 10, wherein the variable distance isproportional to a length of the line piece.
 12. The method of claim 9,wherein the vertical extension step is configured to have one or moreextension line pieces upward and downward of fringe line pieces, lengthsof these extended line pieces are equal or in proportional to lengths ofcorresponding fringe line pieces.
 13. The method of claim 12, whereinthe length of extension line piece is proportional to a length ofcorresponding fringe line piece and number of extension line pieces. 14.The method of claim 9, wherein the rectangular extension step isconfigured to find out an enlarged palm rectangle covering the wholepalm line piece group.
 15. The method of claim 14, wherein the enlargedpalm rectangle is a smallest palm rectangle.
 16. The method of claim 1,further comprises determining whether the palm line piece group needs tobe divided before extending the palm line piece group.
 17. The method ofclaim 16, wherein the step of determining whether the palm line piecegroup needs to be divided comprises one or any combination of thefollowing conditions: determining whether a length sum of line pieces ofthe line piece group is larger than a palm line piece group lengththreshold; and determining whether lengths of line pieces in the linepiece group are arranged in ascent order and descent order for a certaintimes.
 18. The method of claim 16, further comprises: searching forrelative low points of signal values along a central profile of the linepiece group; and dividing the line piece group by the relative lowpoints if it is determined that the palm line piece group needs to bedivided.
 19. The method of claim 16, further comprises: searching forline pieces with lengths shorter than a length threshold; and dividingthe line piece group by the line pieces with lengths shorter than thelength threshold if it is determined that the palm line piece groupneeds to be divided.
 20. The method of claim 16, further comprises:searching for line pieces shorter than neighboring line pieces; anddividing the line piece group by the line pieces shorter thanneighboring line pieces if it is determined that the palm line piecegroup needs to be divided.
 21. The method of claim 20, furthercomprises: searching for two neighboring line pieces having the samelength and shorter than other neighboring line pieces; and dividing theline piece group by the line pieces having the same length if it isdetermined that the palm line piece group needs to be divided.
 22. Themethod of claim 16, wherein if a line piece group is divided intomultiple second line piece groups, the second line piece groups are notpart of the extended palm line piece group.
 23. An apparatus forexcluding a line piece group corresponding to a palm, wherein theapparatus is configured to perform the following steps: gatheringmultiple line piece groups; determining whether one or more palm linepiece groups exist among the multiple line piece groups; extending theone or more palm line piece groups; and excluding the extended palm linepiece group.
 24. The apparatus of claim 23, wherein the apparatus isfurther configured for: determining whether the time of acquiring themultiple line piece groups is in a valid period of a time stamp;loosening condition for determining the palm line piece group if thetime is determined in the valid period of the time stamp; and recoveringcondition for determining the palm line piece group if the time is notdetermined in the valid period of the time stamp.
 25. The apparatus ofclaim 24, wherein apparatus is further configured for updating the validperiod of the time stamp if the palm line piece group exists.
 26. Theapparatus of claim 23, wherein in determining whether one or more palmline piece groups exist among the multiple line piece groups, theapparatus is further configured for: taking a line piece group is a palmline piece group if a signal value of a line piece of the line piecegroup is larger than a palm signal threshold.
 27. The apparatus of claim23, wherein in determining whether one or more palm line piece groupsexist among the multiple line piece groups, the apparatus is furtherconfigured for: taking a line piece group is a palm line piece group ifa length of a line piece of the line piece group is larger than a palmlength threshold.
 28. The apparatus of claim 23, wherein in determiningwhether one or more palm line piece groups exist among the multiple linepiece groups, the apparatus is further configured for: taking a linepiece group is a palm line piece group if quantity of line pieces of theline piece group is larger than a palm line piece quantity threshold.29. The apparatus of claim 24, wherein in loosening condition fordetermining the palm line piece group comprises reducing one or anycombination of the following thresholds: a palm signal threshold; a palmlength threshold; and a palm line piece quantity threshold.
 30. Theapparatus of claim 24, wherein in recovering condition for determiningthe palm line piece group comprises recovering one or any combination ofthe following thresholds: a palm signal threshold; a palm lengththreshold; and a palm line piece quantity threshold.
 31. The apparatusof claim 23, wherein in extending the one or more palm line piecegroups, the apparatus is further configured for performing one or anycombination of the following steps: a horizontal extension step; avertical extension step; and a rectangular extension step.
 32. Theapparatus of claim 31, wherein the horizontal extension step isconfigured to extend each line piece in the line piece group forward andbackward a fixed distance or a variable distance.
 33. The apparatus ofclaim 32, wherein the variable distance is proportional to a length ofthe line piece.
 34. The apparatus of claim 31, wherein the verticalextension step is configured to have one or more extension line piecesupward and downward of fringe line pieces, lengths of these extendedline pieces are equal or in proportional to lengths of correspondingfringe line pieces.
 35. The apparatus of claim 34, wherein the length ofextension line piece is proportional to a length of corresponding fringeline piece and number of extension line pieces.
 36. The apparatus ofclaim 31, wherein the rectangular extension step is configured to findout an enlarged palm rectangle covering the whole palm line piece group.37. The apparatus of claim 36, wherein the enlarged palm rectangle is asmallest palm rectangle.
 38. The apparatus of claim 23, wherein theapparatus is further configured for determining whether the palm linepiece group needs to be divided before extending the palm line piecegroup.
 39. The apparatus of claim 38, wherein the determining whetherthe palm line piece group needs to be divided comprises one or anycombination of the following conditions: determining whether a lengthsum of line pieces of the line piece group is larger than a palm linepiece group length threshold; and determining whether lengths of linepieces in the line piece group are arranged in ascent order and descentorder for a certain times.
 40. The apparatus of claim 38, wherein theapparatus is further configured for: searching for relative low pointsof signal values along a central profile of the line piece group; anddividing the line piece group by the relative low points if it isdetermined that the palm line piece group needs to be divided.
 41. Theapparatus of claim 38, wherein the apparatus is further configured for:searching for line pieces with lengths shorter than a length threshold;and dividing the line piece group by the line pieces with lengthsshorter than the length threshold if it is determined that the palm linepiece group needs to be divided.
 42. The apparatus of claim 38, whereinthe apparatus is further configured for: searching for line piecesshorter than neighboring line pieces; and dividing the line piece groupby the line pieces shorter than neighboring line pieces if it isdetermined that the palm line piece group needs to be divided.
 43. Theapparatus of claim 42, wherein the apparatus is further configured for:searching for two neighboring line pieces having the same length andshorter than other neighboring line pieces; and dividing the line piecegroup by the line pieces having the same length if it is determined thatthe palm line piece group needs to be divided.
 44. The apparatus ofclaim 38, wherein if a line piece group is divided into multiple secondline piece groups, the second line piece groups are not part of theextended palm line piece group.